Piperazine Pyrophosphate, PAPP, 66034-17-1
PIPERAZINE PYROPHOSPHATE (PAPP)
Next-Generation Halogen-Free Intumescent Flame Retardant
SECTION 1: CHEMICAL PRODUCT IDENTIFICATION
| Parameter |
Description |
| Trade Name |
Piperazine Pyrophosphate (PAPP) |
| Chemical Family |
Piperazine Salt Complex / Organic Phosphate |
| Use Area |
Primary acid and carbon source component of high-performance, halogen-free (HFFR) intumescent flame retardant systems for polyolefins (PP, PE), thermoplastic elastomers (TPE, TPU), and engineering plastics. |
SECTION 2: CHEMICAL COMPOSITION AND STRUCTURAL FRAMEWORK
PAPP is a nitrogen-phosphorus synergistic salt with high thermal stability, formed by the stoichiometric combination of a piperazine ring with a pyrophosphate moiety.
| Parameter |
Document Value |
Verified Database Value |
| CAS Registry Number |
66034-17-1 |
66034-17-1 |
| IUPAC Name |
piperazine; phosphono dihydrogen phosphate |
Diphosphoric acid, compd. with piperazine (1:1) |
| Molecular Formula |
C₄H₁₂N₂O₇P₂ |
C₄H₁₄N₂O₇P₂ |
| Molecular Weight |
262.10 g/mol |
264.11 g/mol |
| EC Number |
— |
457-330-7 |
| Density |
— |
1.71 g/cm³ |
Structural Significance: PAPP integrates acid, carbon, and gas source functions into a single molecule through "three-in-one source" technology . This single-molecule design eliminates the phase separation, migration, and char stoichiometry inconsistency issues observed in conventional physical blend intumescent systems (such as APP/PER/MEL) .
SECTION 3: PHYSICAL AND CHEMICAL PROPERTIES
| Property |
Value |
Source/Note |
| Physical State |
White or off-white, odorless, crystalline powder |
Document data |
| Phosphorus (P) Content |
22.0% – 24.0% |
Document data |
| Nitrogen (N) Content |
10.0% – 12.0% |
Document data |
| Moisture / Volatile Content |
≤ 0.5% (105°C, 2 hours) |
Document data |
| pH Value (10% aqueous suspension) |
4.0 – 6.0 |
Document data |
| Water Solubility |
≤ 0.1 g/100 mL (25°C) per document; 0.15 g/100 mL water reported in synthesis literature ; 12.24 g/L at 20°C per ChemicalBook |
Discrepancy noted; synthesis literature value (0.15 g/100 mL) is consistent with the document's "very low solubility" claim |
| Decomposition Point |
324-326°C (DSC) |
Patent data |
Verified Data Note: The water solubility discrepancy between sources (0.15 g/100 mL vs. 12.24 g/L) likely reflects differences in measurement conditions, particle size, and crystal form. The synthesis literature value of 0.15 g/100 mL aligns with the document's characterization of PAPP as having high leaching resistance in polymer matrices.
SECTION 4: THERMAL PERFORMANCE AND DEGRADATION PROFILE
Thermogravimetric Analysis (TGA) data under nitrogen atmosphere:
| Parameter |
Document Value |
Verified Literature Value |
| Thermal Onset (1% Mass Loss) |
≥ 285°C |
Pure PAPP powder: 313°C; MPP/PAPP intumescent coating: 296°C |
| Maximum Decomposition (50% Mass Loss) |
~360°C |
Char residue at 800°C: 33.8 wt% (MPP/PAPP system) |
| Processing Limit |
Safe for PP processing (200-240°C) |
Wider processing window than APP-based systems; suitable for engineering thermoplastics processed above 250°C |
Comparative Advantage: PAPP-based intumescent systems provide a 74°C advantage in 1% mass loss temperature compared to conventional APP/PER/MEL systems (296°C vs. 222°C). This enables safe use in high-temperature engineering resins where APP-based systems would undergo premature degradation .
SECTION 5: PARTICLE SIZE DISTRIBUTION (PSD) METRICS
| Grade |
D₅₀ |
D₉₈ |
Application |
| Standard Grade |
≤ 5.0 μm |
≤ 15.0 μm |
General PP/PE injection molding |
| Micronized / Ultra-Fine |
≤ 2.5 μm |
≤ 8.0 μm |
Cable sheaths, thin-wall profiles |
SECTION 6: DETAILED INDUSTRIAL APPLICATIONS
Piperazine Pyrophosphate is preferred in areas where conventional flame retardants (such as Ammonium Polyphosphate) prove insufficient in water resistance and thermal stability:
Polypropylene (PP) and Polyethylene (PE): Provides highly efficient flame retardancy in automotive parts, electrical appliance panels, and electronic component housings.
Thermoplastic Elastomers (TPE/TPU): Enables halogen-free formulation in cable insulation and profile extrusion without compromising flexibility.
Lithium-Ion Battery Enclosures: Enhances fire resistance of PP plastics in battery cell carriers and module covers in automotive and energy storage sectors. Use in synergistic intumescent formulations for glass fiber reinforced PP-based EV battery housings is documented in literature.
SECTION 7: INDUSTRIAL R&D AND EXAMPLE FORMULATIONS
| Components |
Recipe 1: Polypropylene (PP) |
Recipe 2: TPU (Cable Sheath) |
Recipe 3: Glass Fiber PP |
| Polymer Matrix |
75.0% (Pure PP Homopolymer) |
68.0% (Ester-Based TPU) |
53.0% (PP Copolymer) |
| PAPP |
18.0% (Acid/Carbon Source) |
22.0% (Micronized) |
15.0% (PAPP) |
| Synergist (Melamine Cyanurate/Phosphate) |
6.0% (Gas Source / MCA) |
- |
5.0% (Melamine Phosphate) |
| Glass Fiber (Chopped) |
- |
- |
25.0% |
| Lubricant / Process Aid |
0.5% (Calcium Stearate) |
0.3% (Silicone Oil) |
0.4% (E-Wax) |
| Antioxidant (AO 1010 / 168) |
0.5% |
0.7% |
0.6% |
| Mold Release / Modifier |
- |
9.0% (EVA/Graft Copolymer) |
1.0% |
| Target UL 94 Rating |
V-0 (1.6 mm) |
V-0 (0.8 mm / Low Smoke) |
V-0 (1.6 mm) |
Verified Data Note: Literature confirms that PAPP/MPP synergistic systems achieve UL-94 V-0 in PP, and in structural steel coatings maintain a backside temperature of 170°C in a 2-hour torch test (compared to 326°C for APP-based systems) .
SECTION 8: HAZARD IDENTIFICATION (GHS CLASSIFICATION)
| Parameter |
Assessment |
Source/Note |
| Classification |
Not classified as hazardous substance under EC 1272/2008 (CLP) |
Commercial product SDS |
| Signal Word |
None |
Document data |
| Physical Hazards |
Dust clouds may form explosive mixtures with static discharge |
Document data |
| EPA Assessment |
"Medium" concern for eye irritation, respiratory sensitization, and repeated-dose effects; "High" concern for acute toxicity (via piperazine component) |
EPA DfE assessment |
Critical Regulatory Note: The US EPA evaluated a substituted amine phosphate mixture containing piperazine pyrophosphate and flagged concerns for acute toxicity, eye irritation, and respiratory sensitization based on the piperazine component . However, commercial product suppliers declare the product as not classified as hazardous under GHS .
SECTION 9: STABILITY AND REACTIVITY
| Parameter |
Information |
| Chemical Stability |
Stable under recommended storage and normal use conditions |
| Conditions to Avoid |
Excessive temperatures above 285°C, humid air conditions |
| Incompatible Materials |
Strong oxidizing agents, alkaline compounds, strong mineral acids |
| Hazardous Decomposition Products |
CO, CO₂, NOₓ, P₂O₅ fumes |
SECTION 10: REGULATORY STATUS AND ENVIRONMENTAL DECLARATIONS
| Parameter |
Status |
Source/Note |
| TSCA (USA) |
Piperazine component listed as "Active" in TSCA inventory |
Fisher SDS for piperazine |
| REACH (EU) |
Piperazine has REACH Annex XVII restriction (Entry 75); PAPP itself has no SVHC listing |
Fisher SDS |
| RoHS/WEEE |
Compliant; contains no PBB, PBDE, or phthalates |
Document data |
| Halogen-Free |
Contains no chlorine, bromine, or fluorine |
Commercial product SDS |
SECTION 11: FIRST AID MEASURES
| Exposure |
Action |
| Inhalation |
Move to fresh air; consult doctor if cough or chest tightness persists |
| Skin |
Remove contaminated clothing; wash with plenty of water and soap |
| Eyes |
Hold eyelids open and rinse with plenty of water for at least 15 minutes; remove contact lenses if present |
| Ingestion |
Rinse mouth with water; never give anything by mouth to an unconscious person; do not induce vomiting, consult doctor |
SECTION 12: FIREFIGHTING MEASURES
| Parameter |
Information |
| Extinguishing Media |
CO₂, dry chemical powder, alcohol-resistant foam, water spray |
| Special Hazards |
Dense smoke and toxic phosphorus/nitrogen oxide gases may be released |
| Protective Equipment |
SCBA + full protective clothing |
SECTION 13: ACCIDENTAL RELEASE MEASURES
| Parameter |
Information |
| Personal Precautions |
Dust mask, gloves, protective goggles; avoid dust generation |
| Environmental Precautions |
Prevent entry into sewers, lakes, streams, and groundwater |
| Cleaning |
Wet sweeping or ATEX industrial vacuum; seal waste containers |
SECTION 14: HANDLING AND STORAGE
| Parameter |
Information |
| Handling |
Minimize dust generation; provide good local ventilation; ground transfer lines and silos |
| Storage |
Keep in tightly closed original packaging; store in cool, dry, moisture-free areas away from direct sunlight; do not leave exposed outdoors due to hygroscopic tendency |
SECTION 15: EXPOSURE CONTROLS AND PERSONAL PROTECTION
| Parameter |
Recommendation |
| Engineering Controls |
Closed systems or local exhaust fans |
| Eyes |
Safety goggles with side shields (EN 166) |
| Skin |
Nitrile work gloves, long-sleeved cotton work coveralls |
| Respiratory |
EN 149 approved P2 or P3 filter dust masks in high-dust areas |
SECTION 16: TOXICOLOGICAL INFORMATION
| Parameter |
Value |
Source/Note |
| Acute Oral Toxicity |
LD₅₀ (Rat) > 2000 mg/kg |
Document data |
| Skin/Eye Sensitization |
Mild mechanical irritation (redness, itching) possible |
Document data; EPA flagged eye irritation concern |
| Chronic Toxicity/Carcinogenicity |
No evidence of carcinogenic, mutagenic, or reproductive toxicity |
Document data; EPA flagged "medium" concern |
SECTION 17: ECOLOGICAL INFORMATION
| Parameter |
Value |
Source/Note |
| Ecotoxicity |
Low acute toxicity risk in aquatic ecosystems due to low solubility |
Document data |
| Persistence |
Stable in nature for extended periods; slowly decomposes to orthophosphates and piperazine derivatives via hydrolysis |
Document data; EPA flagged "high persistence" concern |
| Bioaccumulation |
Log Kow ≤ 0; no accumulation tendency |
Document data; estimated Log Kow < -2 |
SECTION 18: DISPOSAL CONSIDERATIONS
| Parameter |
Information |
| Waste Management |
Do not mix with household waste; send to licensed chemical waste incineration/disposal facilities |
| Packaging Disposal |
Completely emptied bags should be disposed of according to local recycling or non-hazardous industrial packaging regulations |
SECTION 19: TRANSPORT INFORMATION
| Parameter |
Information |
| ADR/RID (Road) |
Not classified (Non-hazardous cargo) |
| IMDG (Sea) |
Not classified as dangerous goods |
| IATA (Air) |
No restrictions or special permits required |
| Transport Precaution |
Palletize to prevent puncturing and contact with water/rain |
SECTION 20: REGULATORY LAWS AND DOCUMENT CONTROL
| Parameter |
Status |
| National Legislation |
Compliant with 1272/2008/EC CLP regulation |
| Document Revision No. |
4.0 (2026 Update) |
| Legal Disclaimer |
The data in this document are based on standard laboratory test results. Variations in other additives, pigments, or processing temperatures in polymer formulations may affect final performance. Pilot-scale R&D trials prior to industrial mass production are the user's responsibility. |
Disclaimer: This TDS/SDS is for informational purposes only and is based on available data. Product performance may vary depending on polymer matrix, processing conditions, and formulation. The user is solely responsible for determining the suitability of the product for their specific application and for complying with all applicable local, national, and international regulations. This document is not a substitute for the official SDS provided by the manufacturer.
